A steam engine is to have its thermal efficiency improved...

A steam engine is to have its thermal efficiency improved from $8.00 \%$ to $10.0 \%$ while continuing to produce 4500 J of useful work each cycle. (a) Does the ratio of the heat output to heat input (1) increase, (2) remain the same, or (3) decrease? Why? (b) What is the change in $Q_{c} / Q_{h}$ in this example?

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Energy Balance in Thermodynamic Cycles

The energy balance in a thermodynamic cycle ensures that the total energy input as heat is partitioned between the useful work output and the discarded heat. Recognizing this balance helps in understanding the impact of efficiency improvements, as a constant work output with higher efficiency leads to a lower heat input and, consequently, a lower ratio of waste heat to total heat input.

Thermal Efficiency

Thermal efficiency is the ratio of the work output of a heat engine to the heat input, indicating how effectively the engine converts thermal energy into work. It is defined by the formula ? = W/Q?, and understanding this concept is crucial when analyzing how changes in efficiency impact the operating conditions and energy flows within heat engines.

Heat Transfer Ratios in Heat Engines

In a heat engine, the ratio of heat rejected (Q?) to heat input (Q?) is directly related to the engine's efficiency through the relation Q?/Q? = 1 - ?. This concept is important because any improvement in efficiency (?) implies a decrease in the fraction of heat that is wasted, which is reflected as a decrease in the Q?/Q? ratio.

Transcript

Please give Ace some feedback